Table 4

Adjusted ORs (95% CIs) for changes in CRS practices between pre-legislation and post-legislation in Shenzhen

Variables	Model 1			Model 2
Variables	CRS possession	CRS use	Appropriate CRS use	CRS possession	CRS use	Appropriate CRS use
Overall	6.631 (6.053 to 7.264)*	4.239 (3.866 to 4.648)*	0.727 (0.629 to 0.852)*	8.207 (7.425 to 9.072)*	4.955 (4.487 to 5.471)*	0.787 (0.609 to 0.956)*
2–3 years (vs 0–1 years)	1.410 (1.244 to 1.599)*	1.473 (1.295 to 1.675)*	5.613 (3.996 to 7.885)*	1.271 (1.115 to 1.449)*	1.313 (1.147 to 1.504)*	5.483 (3.898 to 7.713)*
4–6 years (vs 0–1 years)	2.012 (1.820 to 2.225)*	1.732 (1.562 to 1.920)*	0.598 (0.497 to 0.719)*	1.660 (1.494 to 1.845)*	1.385 (1.242 to 1.546)*	0.564 (0.467 to 0.682)*
Boy (vs girl)	1.033 (0.955 to 1.116)	1.046 (0.968 to 1.130)	0.918 (0.805 to 1.046)	1.054 (0.972 to 1.143)	1.068 (0.985 to 1.159)	0.921 (0.807 to 1.051)
Male (vs female)	1.015 (0.933 to 1.105)	1.102 (1.014 to 1.198)*	0.857 (0.746 to 0.985)*	0.952 (0.872 to 1.040)	1.031 (0.944 to 1.126)	0.840 (0.730 to 0.966)*
College or above (vs <college)	1.529 (1.395 to 1.675)*	1.755 (1.597 to 1.929)*	1.340 (1.135 to 1.582)*	1.154 (1.048 to 1.272)*	1.295 (1.171 to 1.433)*	1.241 (1.044 to 1.475)*
High car price (vs low)	1.587 (1.467 to 1.717)*	1.601 (1.480 to 1.732)*	1.005 (0.880 to 1.148)	1.352 (1.243 to 1.469)*	1.348 (1.240 to 1.466)*	0.919 (0.801 to 1.055)
Higher trip frequency (vs low)	2.060 (1.795 to 2.364)*	2.248 (1.956 to 2.583)*	1.425 (1.126 to 1.804)*	1.637 (1.415 to 1.894)*	1.763 (1.519 to 2.045)*	1.385 (1.084 to 1.770)*
High trip frequency (vs low)	1.636 (1.449 to 1.847)*	1.831 (1.615 to 2.075)*	1.459 (1.169 to 1.820)*	1.266 (1.112 to 1.441)*	1.383 (1.209 to 1.583)*	1.355 (1.076 to 1.707)*
Moderate trip frequency (vs low)	1.239 (1.095 to 1.402)*	1.319 (1.159 to 1.501)*	1.435 (1.139 to 1.809)*	0.979 (0.858 to 1.116)	1.009 (0.879 to 1.158)	1.335 (1.051 to 1.695)*
Longer trip distance (vs short)	1.299 (1.153 to 1.464)*	1.292 (1.147 to 1.456)*	1.176 (0.961 to 1.438)	1.331 (1.173 to 1.511)*	1.322 (1.163 to 1.502)*	1.156 (0.937 to 1.427)
Long trip distance (vs short)	1.300 (1.170 to 1.445)*	1.320 (1.188 to 1.468)*	1.229 (1.026 to 1.472)*	1.228 (1.096 to 1.377)*	1.237 (1.102 to 1.389)*	1.180 (0.976 to 1.426)
Moderate trip distance (vs short)	1.308 (1.179 to 1.452)*	1.302 (1.174 to 1.445)*	1.111 (0.932 to 1.324)	1.243 (1.113 to 1.388)*	1.222 (1.093 to 1.366)*	1.072 (0.894 to 1.284)
Seat-belt use (vs non-use)	1.873 (1.485 to 2.363)*	7.506 (5.164 to 10.910)*	2.399 (1.107 to 5.199)	1.476 (1.159 to 1.879)*	6.323 (4.315 to 9.267)*	2.140 (0.984 to 4.656)
High knowledge score (vs low)	2.584 (2.385 to 2.800)*	2.738 (2.526 to 2.966)*	1.312 (1.144 to 1.505)*	2.379 (2.190 to 2.585)*	2.430 (2.236 to 2.641)*	1.224 (1.061 to 1.412)*

*P value <0.05.
†Model 1: adjusted for child’s age and sex.
‡Model 2: adjusted child’s age and sex, parent’s sex and education level, car price, trip frequency and distance, seat-belt use and knowledge score.
CRS, child restraint system.